Processes for preparing sterol esters

ABSTRACT

A food additive useful for lowering serum cholesterol in humans contains a sterol or stanol ester of a fatty acid or a dicarboxylic acid ester of a sterol or stanol made by reacting a sterol, stanol and a carboxylic acid in the presence of an effective amount of a catalyst selected from the group consisting of calcium oxide, calcium hydroxide, a calcium salt of a carboxylic acid, magnesium hydroxide and combinations thereof described herein below.

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application is a continuation-in-part of copendingapplication Ser. No. 09/072,434, filed on May 4, 1998. This applicationalso claims the benefit of earlier filed and copending provisionalapplication Serial No. 60/069,790, filed on Dec. 16, 1997, the entirecontents of both of the above applications are incorporated herein byreference.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

[0002] Not Applicable.

BACKGROUND OF THE INVENTION

[0003] Phytosterols have been found to be effective in reducing serumcholesterol in humans. Phytosterols are steroids that bear a closestructural relationship to cholesterol but differ in the configurationof the side chains at the 17-position. It is well known thatβ-sitosterol and the fatty acid esters of β-sitosterol are effective inreducing serum cholesterol. Recent studies have found that β-sitostanoland the fatty acid esters of β-sitostanol are particularly effective inreducing serum cholesterol and LDL levels. It has been recently reportedthat the fatty acid esters of β-sitostanol are particularly effectivecholesterol-reducing agents presumably because they are in solution.Such esters can be introduced into the body as additives in foodproducts such as margarine. Margarines containing β-sitosterol and thosecontaining β-sitosterol fatty acid esters as well as margarinescontaining β-sitostanol and β-sitostanol fatty acid esters have beenshown to reduce serum cholesterol levels in humans.

BRIEF SUMMARY OF THE INVENTION

[0004] The present invention pertains to a food additive containing asterol or stanol ester of a fatty acid or a dicarboxylic acid ester of asterol or stanol made by the process described herein below. The foodadditive can be incorporated into food for the purpose of lowering serumcholesterol in humans and/or for reducing the absorption of cholesterolfrom foods and/or beverages. The food additive is prepared by combininga sterol and/or stanol fatty acid ester thereof and/or a dicarboxylicacid ester of a sterol or stanol made by the process described hereinand an edible solubilizing agent, an effective amount of a suitableantioxidant and an effective amount of a suitable dispersant. The steroland/or stanol esters made by the process described herein can be usedwithout removing the catalyst because the catalyst is non-toxic and usedat low levels. Another advantage is that when the fatty acid esters ofsterols or stanols are prepared by transesterification, the ester thatis transesterified can be either a lower alkyl ester such as a methyl oran ethyl ester or a triglyceride which is a triglyceryl ester of a C₆₋₂₂fatty acid such as a conventional fat or oil.

[0005] Another aspect of the invention pertains to a method of reducingthe absorption of cholesterol into the bloodstream which comprisesorally introducing into the body an effective amount of a substancecontaining a β-sitostanol ester made by reacting a stanol and acarboxylic acid in the presence of an effective amount of a catalystselected from the group consisting of calcium oxide, calcium hydroxide,a calcium salt of a carboxylic acid, magnesium hydroxide andcombinations thereof.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING

[0006] Not Applicable.

DETAILED DESCRIPTION OF THE INVENTION

[0007] The term sterol is well known to those skilled in the art andgenerally refers to those compounds having aperhydrocyclopentanophenanthrene ring system (the ring system depictedin Formula III herein) and having one or more OH substituents, examplesof which include, but are not limited to, cholesterol, campesterol,ergosterol, sitosterol, and the like. It is common to obtain sterols asmixtures of compounds such as, for example, GENEROL® 122N sterols, atrademark product of Henkel Corporation, Gulph Mills, Pa. GENEROL® 122Nsterol contains 25-30% campesterol, 17-22% stigmasterol and 45-50%sitosterol.

[0008] The term stanol is well known to those skilled in the art andgenerally refers to those compounds having a saturatedperhydrocyclopentanophenanthrene ring system (the ring system depictedin Formula II herein) and having one or more OH substituents, examplesof which include, but are not limited to, campestanol, sitostanol whichalso known as β-sitostanol and stigmastanol, coprostanol, cholestanoland the like.

[0009] The food additive according to the invention is comprised of asterol and/or stanol ester of a fatty acid wherein the ester is made byreacting a sterol and/or stanol with a fatty acid having from 6 to 22carbon atoms in the presence of an effective amount of a catalystselected from the group consisting of calcium oxide, calcium hydroxide,a calcium salt of a carboxylic acid, magnesium hydroxide andcombinations thereof or a dicarboxylic acid ester of a sterol or stanolof the formula I. Since the catalyst is non-toxic and used at lowlevels, the sterol and/or stanol ester of the fatty acid can be addeddirectly to foods without further processing such as removal of thecatalyst. The sterol can be any sterol. Examples of suitable sterolsinclude, but are not limited to, campesterol, ergosterol, stigmasterol,sitosterol or a combination thereof. A preferred sterol is β-sitosterol.A commercially available combination of sterols is GENEROL® 122N sterolsas set forth herein. The stanol can be any stanol. Examples of suitablestanols include, but are not limited to, campestanol, sitostanol whichis also known as β-sitostanol and stigmastanol, coprostanol, cholestanoland the like. A preferred stanol is β-sitostanol.

[0010] The amount of sterol and/or stanol fatty acid ester that can beused in the food additive is an effective amount which is any amountnecessary to either reduce serum cholesterol in humans after ingestionof a food containing the food additive or an amount necessary to reducethe absorption of cholesterol from foods and/or beverages. A preferredfood additive composition of the instant invention comprises from about70% to about 80% vegetable oil, from about 1% to about 2% tocopherols,and from about 10% to about 25% sterol and/or stanol fatty acid esterprepared by the method according to the invention.

[0011] The food additive is prepared by combining a sterol and/or stanolester of a fatty acid made by the process described herein and an ediblesolubilizing agent, an effective amount of a suitable antioxidant and aneffective amount of a suitable dispersant. The solubilizing agent can bevegetable oil such as, for example, sunflower oil, palm kernel oil,coconut oil, rape seed oil, tallow, corn oil, canola oil, linseed oil,palm oil, olive oil, sesame oil, safflower oil, and the like,monoglycerides, diglycerides, triglycercides, tocopherols, and the like,and mixtures thereof. The antioxidant can be ascorbic acid (Vitamin C),tocopherols such as α-tocopherol (vitamin E), β-carotene, an extract ofthe bark of the maritime pine, Pinus maritima and combinations thereof.The extract of the bark of the maritime pine, also known as PYCNOGENOL™,contains procyanidines consisting of catechin and epicatechin unitslinked by C—C bonds to form dimers, trimers and other oligomers up to achain length of 6-7 molecules and phenolic acids and its glucosederivatives. PYCNOGENOL™ is produced according to U.S. Pat. No.4,698,360, which is incorporated herein for reference. The extract usedaccording to the invention may be prepared essentially by extractingmaritime pine bark in comminuted form with boiling water, saturating thefiltered extract with sodium chloride or, alternatively, adding ammoniumsulfate to 20% w/v, separating the precipitate formed, repeatedlyextracting the supernatant with {fraction (1/10)} volume of ethylacetate, drying the collected ethyl acetate extracts, concentrating thedried extract, pouring it into 3 volumes of chloroform with stirring andcollecting the precipitate which may be purified by repeating thedissolution in ethyl acetate and precipitation with chloroform. Mixturesof the above antioxidants can also be used.

[0012] A suitable dispersant is any biologically acceptable surfaceactive agent, examples of which include, but are not limited to, analkyl polyglycoside, lecithin, polysorbate 80, sodium lauryl sulfate,and the like. The alkyl polyglycosides which can be used in theinvention have the formula V

R₁O(R₂O)_(b)(Z)_(a)  V

[0013] wherein R₁ is a monovalent organic radical having from about 6 toabout 30 carbon atoms; R₂ is a divalent alkylene radical having from 2to 4 carbon atoms; Z is a saccharide residue having 5 or 6 carbon atoms;b is a number having a value from 0 to about 12; a is a number having avalue from 1 to about 6. Preferred alkyl polyglycosides which can beused in the compositions according to the invention have the formula Iwherein Z is a glucose residue and b is zero. Such alkyl polyglycosidesare commercially available, for example, as APG®, GLUCOPON®, PLANTAREN®or AGRIMUL® surfactants from Henkel Corporation, Ambler, Pa., 19002.Examples of such surfactants include but are not limited to:

[0014] 1. GLUCOPON® 220 Surfactant—an alkyl polyglycoside in which thealkyl group contains 8 to 10 carbon atoms and having an average degreeof polymerization of 1.5.

[0015] 2. GLUCOPON® 225 Surfactant—an alkyl polyglycoside in which thealkyl group contains 8 to 10 carbon atoms and having an average degreeof polymerization of 1.7.

[0016] 3. GLUCOPON® 600 Surfactant—an alkyl polyglycoside in which thealkyl group contains 12 to 16 carbon atoms and having an average degreeof polymerization of 1.4.

[0017] 4. GLUCOPON® 625 Surfactant—an alkyl polyglycoside in which thealkyl group contains 12 to 16 carbon atoms and having an average degreeof polymerization of 1.4.

[0018] 5. APG® 325 Surfactant—an alkyl polyglycoside in which the alkylgroup contains 9 to 11 carbon atoms and having an average degree ofpolymerization of 1.6.

[0019] 6. PLANTAREN® 2000 Surfactant—an alkyl polyglycoside in which thealkyl group contains 8 to 16 carbon atoms and having an average degreeof polymerization of 1.4.

[0020] 7. PLANTAREN® 1300 Surfactant—an alkyl polyglycoside in which thealkyl group contains 12 to 16 carbon atoms and having an average degreeof polymerization of 1.6.

[0021] 8. AGRIMUL® PG 2067 Surfactant—an alkyl polyglycoside in whichthe alkyl group contains 8 to 10 carbon atoms and having an averagedegree of polymerization of 1.7.

[0022] Other examples include alkyl polyglycoside surfactantcompositions which are comprised of mixtures of compounds of formula Ias described in U.S. Pat. No. 5,266,690 and 5,449,763, the entirecontents of both of which are incorporated herein by reference.

[0023] The method by which the novel food additive composition is usedto reduce cholesterol absorption from foods and beverages includes thestep of commingling the food additive composition with foods andbeverages, mixing until uniformly blended. The novel food additive iseffective as an additive in margarine, cooking oils or shortening forthe purpose of reducing serum cholesterol in humans who ingest foodproducts made with the novel additive. Margarine containing the novelfood additive can be made by methods well known to those skilled. Ageneral method for making margarine is disclosed in pages 77-84 ofVolume 3 of Bailey's Industrial Oil and Fat Products (1985), the entirecontents of which are incorporated herein by reference. The amount ofsterol and/or stanol fatty acid ester useful in the novel food additiveis an effective amount which is any amount necessary to either reduceserum cholesterol in humans after ingestion of a food containing thefood additive or an amount necessary to reduce the absorption ofcholesterol from foods and/or beverages. A preferred food additivecomposition of the instant invention comprises from about 70% to about80% vegetable oil, from about 1% to about 2% tocopherols, and from about10% to about 25% sterol and/or stanol fatty acid ester prepared by themethod according to the invention. Particularly preferred compositionsare composed of from about 70% to about 80% sunflower oil and/or rapeseed oil, from about 1% to about 2% vitamin E and/or an extract of thebark of the maritime pine, Pinus maritima and from about 10% to about25% of a sterol and/or stanol fatty acid ester prepared by the methodaccording to the invention.

[0024] Another aspect of the invention pertains to a method of reducingthe absorption of cholesterol into the bloodstream which comprisesorally introducing into the body an effective amount of a substancecontaining a β-sitostanol ester made by reacting β-sitostanol and acarboxylic acid in the presence of an effective amount of a catalystselected from the group consisting of calcium oxide, calcium hydroxide,a calcium salt of a carboxylic acid, magnesium hydroxide andcombinations thereof. The cholesterol-lowering ability of fatty acidesters of β-sitostanol is described in U.S. Pat. No. 5,502,045, theentire contents of which are incorporated herein by reference. The fattyacid esters of β-sitostanol made by the process described herein can beorally introduced by ingesting food products containing the foodadditives of the present invention. Preferred methods of oralintroduction of the β-sitostanol made by the process described herein isthrough the ingestion of margarine, cooking oils or shorteningcontaining a food additive according to the invention. A particularlyeffective amount of β-sitostanol fatty acid esters is from about 0.2 toabout 20 grams per day. Particularly preferred additives are composed offrom about 70% to about 80% sunflower oil and/or rape seed oil, fromabout 1% to about 2% vitamin E and/or an extract of the bark of themaritime pine, Pinus maritima and from about 10% to about 25% of aβ-sitostanol fatty acid ester prepared by the method according to theinvention.

[0025] In regard to the esterification process used to make the steroland/or stanol esters which can be used in the novel food additive, anyaliphatic, cycloaliphatic, or aromatic mono- or poly-carboxylic acidhaving at least 2 carbon atoms or mixtures of such acids can be used inthe process according to the invention. Examples of aliphaticmono-carboxylic acids include, but are not limited to acetic, propionic,valeric, pelargonic, palmitic, lauric, oleic, linoleic acid, and thelike. Examples of cycloaliphatic mono-carboxylic acids include, but arenot limited to cyclopentane carboxylic acid, cyclohexane carboxylicacid, cyclohexene carboxylic acid and the like. Examples of aromaticmono-carboxylic acids include, but are not limited to benzoic acid,toluic acid, aminobenzoic acid and the like. Examples of aliphaticpoly-carboxylic acids include, but are not limited to oxalic, malonic,adipic, azelaic acid, C-36 dimer acid, citric acid and the like.Examples of aromatic poly-carboxylic acids include, but are not limitedto phthalic acid, trimellitic acid and the like. Preferred carboxylicacids are mixtures of long chain carboxylic acids such as those derivedfrom naturally occurring oils such as sunflower oil, palm kernel oil,coconut oil, rape seed oil, tallow, corn oil, canola oil, linseed oil,palm oil, olive oil, sesame oil, safflower oil, and the like which areknown to those skilled in the art and are disclosed in chapter 6 ofVolume 1 of the fourth edition (1979) of Bailey's Industrial Oil and FatProducts, the entire contents of which are incorporated herein byreference. Preferred fatty acid mixtures are those obtained fromsunflower oil and rape seed oil.

[0026] The direct or transesterification modifications of theesterification processes can be carried out in the presence of a calciumoxide, calcium hydroxide, a calcium salt of a carboxylic acid, magnesiumhydroxide catalyst or a combination of such catalysts. One advantage ofthe method according to the invention is that the calcium or magnesiumcatalysts can be left in the product or removed by contacting thereaction product with a chelating agent such as L-tartaric acid or EDTA.The preferred catalysts are calcium hydroxide, calcium oxide and thecalcium salt of a fatty acid having from about 10 to about 22 carbonatoms. Calcium oxide is a particularly preferred catalyst. The amountthat can be used is an effective amount which is any amount required toeffect the conversion of a sterol or stanol to the corresponding ester.Typically, the amount will range from about 0.01% to 0.2% based on thetotal weight of the reaction mixture and will preferably be in the rangeof about 0.02% to about 0.05%.

[0027] The processes according to the invention can be carried out at atemperature in the range of from about 190° C. to about 210° C. Thetemperature for a particular reaction will depend upon a number offactors such as the nature of the catalyst, the equipment in which thereaction is carried out and whether a sterol or stanol is esterified ortransesterified. If a sterol is used in the process according to theinvention, a temperature in the range of 190° C. to about 210° C. isoptimum. Such a temperature will minimize the dehydration of the sterol.If a stanol is used in the process according to the invention, atemperature up to about 210° C. is optimum.

[0028] The transesterification process according to the invention can becarried out using any type of carboxylic acid ester. Such esters includesimple esters such as lower alkyl esters which include, for example,methyl, ethyl, propyl, or butyl esters or higher alkyl esters such aspentyl, hexyl, heptyl and the like or triglycerides which aretriglyceryl esters of C₆₋₂₂ fatty acids such as conventional fats oroils. The transesterification conditions will vary according to the typeof ester employed. If a glyceride is used, the temperature will be inthe range of from about 210° C. to about 250° C., preferably from about220° C. to about 230° C. If an ester of a lower molecular weight alcoholis used such as a methyl or ethyl ester such that the alcohol formedwill be readily removed under the reaction conditions as, opposed to theuse of a triglyceride where the glycerin formed is not as readilyremoved, the temperature will be in the range of from about 100° C. toabout 130° C., preferably from about 110° C. to about 120° C.

[0029] The direct esterification process according to the invention canbe carried out by mixing the reactants in a batch reactor and heatingthe reactor contents to an appropriate temperature to remove the waterof reaction. This may be accomplished at atmospheric pressure or below.Another method of carrying out the process according to the invention isto pass the reaction mixture through an evaporator such as a thin filmevaporator or wiped film evaporator operating at a pressure of about 2-3millibars and at a temperature of about 230° C. while the reaction istaking place or after the reaction has been completed. It is preferableto operate the evaporator using an inert gas or vapor such as nitrogenor steam such that the inert gas or vapor contacts the thin film ofreaction mixture in a counter-current fashion. The reaction mixture ispassed through the evaporator one or more times in order to increase thesurface to volume ratio to more efficiently remove the water of reactionthereby decreasing the time the reaction mixture spends at elevatedreaction temperatures. One embodiment of the aforementioned method is acombination of a stirred tank reactor and an evaporator wherein thereactants are heated to reaction temperature and then repeatedlycirculated through the evaporation means. An advantage of carrying outthe process according to the invention on a commercial scale is thatsince no low molecular weight alcohol is produced as in, for example,transesterification of a methyl ester, there is no foaming in a reactordue to the evolution of the low molecular weight alcohol such asmethanol. Therefore, the full working volume of the reactor can beutilized without an allowance for foam volume.

[0030] The process according to the invention is particularly useful forthe preparation of dicarboxylic acid esters of sterols and/or stanolswherein the dicarboxylic acids are fully esterified or partiallyesterified. Such compounds have the formula I

[0031] wherein R¹ is an aliphatic or aromatic moiety having from one toabout 36 carbon atoms. Examples of possible values of R¹ include, butare not limited to, branched and unbranched alkylene and alkenyleneradicals having from 2 to 18 carbon atoms; dimer acid residues which arecycloaliphatic moieties having 34 carbon atoms; aromatic radicals andeach of R² and R³ is hydrogen, or a radical of the formula II or formulaIII

[0032] wherein R⁴ is an alkyl, substituted alkyl, alkenyl or substitutedalkenyl group having from one to about 10 carbon atoms; each of R² or R³is independently hydrogen with the proviso that only one of R² or R³ canbe hydrogen. In the instances where only one of R² or R³ is hydrogenrefer to the partial or half esters of the dicarboxylic acids. Thesecompounds are useful as for reducing serum cholesterol and LDL levels.Preferred compounds of the formula I include those wherein R¹ is analkylene radical having from 2 to 18 carbon atoms with alkylene radicalshaving 7, 8, 10, and 11 carbons being especially preferred; each of R²and R³ is a radical of the formula II wherein R⁴ is an alkyl radicalhaving from 2 to 10 carbon atoms. Preferred values of R⁴ include abranched alkyl group having 10 carbon atoms. A most preferred R⁴ is analkyl group of the formula IV

[0033] Most preferred compounds of the formula I include thedisitostanol ester of azelaic acid, the disitostanol ester of brassylicacid, the disitostanol ester of decanedioic acid, the disitostanol esterof dodecanedioic acid, the disitosterol ester of azelaic acid, thedisitosterol ester of brassylic acid, the disitostanol ester ofdecanedioic acid and, the disitosterol ester of dodecanedioic acid, thesitostanol monoester of azelaic acid, the sitostanol monoester ofbrassylic acid, the sitostanol monoester of decanedioic acid, thesitostanol monoester of dodecanedioic acid, the sitosterol monoester ofazelaic acid, the sitosterol monoester of brassylic acid, the sitostanolmonoester of decanedioic acid and, the sitosterol monoester ofdodecanedioic acid.

[0034] The following examples are meant to illustrate but not to limitthe invention.

EXAMPLE 1

[0035] About 250 grams of sunflower fatty acid (acid value=200.1) wasadded to a clean, dry vessel under nitrogen, heated to 130° C. withagitation and nitrogen sparge. About 357 grams of mixed stanols(hydrogenated GENEROL® 122N sterol ) was added at a rate slow enough toavoid cooling while agitating with a nitrogen sparge. This requiredabout one half hour. After the addition of the stanol, 0.34 grams ofcalcium hydroxide was added and the pressure was gradually decreased to27 inches, while the temperature was increased to 230° C. After sixhours, the pressure was reduced to 40 mm Hg while maintaining the heatat 230° C. for another six hours. The reaction mixture was cooled undervacuum and the vacuum broken with nitrogen. The acid value at this pointwas 7.4. A solution of 2.7 grams of tartaric acid in 20 ml water wasadded to the crude product at 80° C. with agitation and nitrogen sparge.The mixture was then heated to 110° C. and 27 inches vacuum for a halfhour to remove water. TONSIL® Optimum FF bleaching clay was then addedunder nitrogen, the mixture agitated for a half hour and filteredthrough a bed of CELITE® filter aid on a heated Buchner funnel. Thebatch lightened upon neutralization of the catalyst and filtration.

[0036] Analysis

[0037] Appearance: Clear yellow liquid which sets up to a wax

[0038] Color (Gardner): 5

[0039] Acid Value: 7.35

[0040] % Stanol: 4.4

[0041] Ppm Calcium: 1

EXAMPLE 2

[0042] About 250 grams of sunflower fatty acid (acid value=200.1) wasadded to a clean, dry vessel under nitrogen, heated to 130° C. withagitation and nitrogen sparge. About 357 grams of mixed sterols(GENEROL® 122N sterol) was added at a rate slow enough to avoid coolingwhile agitating with a nitrogen sparge. This required about one halfhour. After the addition of the stanol, 0.34 grams of calcium oxide wasadded and the pressure was gradually decreased to 27 inches, while thetemperature was increased to 210° C. After six hours, the pressure wasreduced to 40 mm Hg while maintaining the heat at 23020 C. for anothersix hours. The reaction mixture was cooled under vacuum and the vacuumbroken with nitrogen. The acid value at this point was 7.4. A solutionof 2.7 grams of tartaric acid in 20 ml water was added to the crudeproduct at 80° C. with agitation and nitrogen sparge. The mixture wasthen heated to 110° C. and 27 inches vacuum for a half hour to removewater. TONSIL® Optimum FF bleaching clay was then added under nitrogen,the mixture agitated for a half hour and filtered through a bed ofCELITE® filter aid on a heated Buchner funnel. The batch lightened uponneutralization of the catalyst and filtration.

EXAMPLE 3

[0043] A dicarboxylic ester is made by reacting one mole of a sterol orstanol with a ½ mole of a dicarboxylic acid in the presence of calciumoxide at 210 degrees under reduced pressure according to the procedureof Examples 1 and 2 above.

EXAMPLE 4

[0044] About 312 grams of sunflower fatty acid (acid value =200.1) wasadded to a clean, dry vessel under nitrogen, heated to 120° C. withagitation and nitrogen sparge. About 357 grams of GENEROL® 122N sterolwas added at a rate slow enough to avoid cooling while agitating with anitrogen sparge. This required about one half hour. After the additionof the GENEROL® 122N, 0.34 grams of calcium oxide was added and thepressure was gradually decreased to 30 mbar while the temperature wasincreased to 210° C. After six hours at 210° C. and <30 mbar, thereaction mixture was cooled under vacuum, and the acid value at thispoint was 22.2. A solution of 3.72 g tartaric acid in 23 g water wasadded to the crude product at 80° C. with agitation and nitrogen sparge.The mixture was then heated to 90° C. and 17 mbar for one hour. Thevacuum was released with nitrogen, added 2 g of TONSIL® FF, 1.4 g ofClarcel DICB, evacuated to <30 mbar and filtered at 90° C. The batchlightened upon neutralization of the catalyst and filtration. The crudeproduct contained 4.7% unreacted sterol via GC analysis.

What is claimed is:
 1. A process for making a food additive comprisingcombining an edible solubilizing agent, an effective amount of asuitable antioxidant, an effective amount of a suitable dispersant and asterol or stanol ester made by reacting a sterol or a stanol and acarboxylic acid in the presence of an effective amount of a catalystselected from the group consisting of calcium oxide, calcium hydroxide,a calcium salt of a carboxylic acid, magnesium hydroxide andcombinations thereof.
 2. The process of claim 1 wherein the sterol isβ-sitosterol.
 3. The process of claim 1 wherein the sterol isβ-sitostanol.
 4. The process of claim 1 wherein the catalyst is calciumhydroxide, calcium oxide or a calcium salt of a carboxylic acid.
 5. Theprocess of claim 1 wherein the carboxylic acid is a carboxylic acidhaving from about 2 to 22 carbon atoms.
 6. A process which comprisesreacting β-sitostanol with a carboxylic acid in the presence of aneffective amount of calcium oxide.
 7. The process of claim 6 wherein thecarboxylic acid is a carboxylic acid having from about 2 to 22 carbonatoms.
 8. The process of claim 1 wherein the carboxylic acid is amixture of long chain carboxylic acids derived from sunflower oil, palmkernel oil, coconut oil, rape seed oil, tallow, corn oil, canola oil,linseed oil, palm oil, olive oil, sesame oil, safflower oil.
 9. Aprocess which comprises reacting β-sitosterol with a carboxylic acid inthe presence of an effective amount of calcium oxide.
 10. The process ofclaim 1 wherein the antioxidant is vitamin C, vitamin E, β-carotene, anextract of the bark of the maritime pine, Pinus maritima, orcombinations thereof.
 11. A food additive composition comprising anedible solubilizing agent, an effective amount of a suitable antioxidantand an effective amount of a suitable dispersant and a sterol or stanolester made by reacting a sterol or a stanol and a carboxylic acid in thepresence of an effective amount of a catalyst selected from the groupconsisting of calcium oxide, calcium hydroxide, a calcium salt of acarboxylic acid, magnesium hydroxide and combinations thereof.
 12. Thecomposition of claim 11 wherein the sterol is β-sitosterol.
 13. Thecomposition of claim 11 wherein the stanol is β-sitostanol.
 14. Thecomposition of claim 11 wherein the catalyst is calcium hydroxide,calcium oxide or a calcium salt of a carboxylic acid.
 15. Thecomposition of claim 11 wherein the carboxylic acid is a carboxylic acidhaving from about 2 to 22 carbon atoms.
 16. The composition of claim 11wherein the antioxidant is vitamin C, vitamin E, β-carotene, an extractof the bark of the maritime pine, Pinus maritima, or combinationsthereof.
 17. The composition of claim 11 wherein the carboxylic acid isa mixture of long chain carboxylic acids derived from sunflower oil,palm kernel oil, coconut oil, rape seed oil, tallow, corn oil, canolaoil, linseed oil, palm oil, olive oil, sesame oil, safflower oil. 18.The composition of claim 17 wherein the mixture of long chain carboxylicacids derived from sunflower oil.
 19. A process which comprises reactingβ-sitosterol with a carboxylic acid in the presence of an effectiveamount of calcium oxide.
 20. The composition of claim 11 wherein theantioxidant is vitamin C, vitamin E, β-carotene, an extract of the barkof the maritime pine, Pinus maritima, or combinations thereof.
 21. Afood additive made by the process comprising combining an ediblesolubilizing agent, an effective amount of a suitable antioxidant, aneffective amount of a suitable dispersant and a sterol or stanol estermade by reacting a sterol or a stanol and a carboxylic acid in thepresence of an effective amount of a catalyst selected from the groupconsisting of calcium oxide, calcium hydroxide, a calcium salt of acarboxylic acid, magnesium hydroxide and combinations thereof.
 22. Thefood additive of claim 21 wherein the sterol is β-sitosterol.
 23. Thefood additive of claim 21 wherein the sterol is β-sitostanol.
 24. Thefood additive of claim 21 wherein the catalyst is calcium hydroxide,calcium oxide or a calcium salt of a carboxylic acid.
 25. The foodadditive of claim 21 wherein the carboxylic acid is a carboxylic acidhaving from about 2 to 22 carbon atoms.
 26. The food additive of claim21 wherein the carboxylic acid is a mixture of long chain carboxylicacids derived from sunflower oil, palm kernel oil, coconut oil, rapeseed oil, tallow, corn oil, canola oil, linseed oil, palm oil, oliveoil, sesame oil, safflower oil.
 27. The food additive of claim 21wherein the antioxidant is vitamin C, vitamin E, β-carotene, an extractof the bark of the maritime pine, Pinus maritima, or combinationsthereof.
 28. A composition comprising an edible solubilizing agent, aneffective amount of a suitable antioxidant, an effective amount of asuitable dispersant and a compound of the formula I

wherein R¹ is an aliphatic or aromatic moiety having from one to about36 carbon atoms and each of R² and R³ is independently hydrogen with theproviso that only one of R² or R³ is hydrogen, or a radical of theformula II or formula III

wherein R⁴ is an alkyl, substituted alkyl, alkenyl or substitutedalkenyl group having from one to about 10 carbon atoms.
 29. Thecomposition of claim 28 wherein R¹ is an alkylene radical having from 2to 18 carbon atoms; each of R² and R³ is a radical of the formula IIwherein R⁴ is an alkyl radical having from 2 to 10 carbon atoms.
 30. Thecomposition of claim 28 wherein R₁ is an alkylene radical having 7carbon atoms and wherein each of R² and R³ is a radical of the formulaII wherein R⁴ is a branched alkyl group having 10 carbon atoms.
 31. Thecomposition of claim 30 wherein said branched alkyl group has theformula IV


32. The composition of claim 28 wherein R¹ is an alkylene radical having8 carbon atoms and wherein each of R² and R³ is a radical of the formulaII wherein R⁴ is a branched alkyl group having 10 carbon atoms.
 33. Thecomposition of claim 32 wherein said branched alkyl group has theformula IV


34. The composition of claim 28 wherein R¹ is an alkylene radical having10 carbon atoms and wherein each of R² and R³ is a radical of theformula II wherein R⁴ is a branched alkyl group having 10 carbon atoms.35. The composition of claim 34 wherein said branched alkyl group hasthe formula IV


36. The composition of claim 28 wherein R¹ is an alkylene radical having11 carbon atoms and wherein each of R² and R³ is a radical of theformula II wherein R⁴ is a branched alkyl group having 10 carbon atoms.37. The composition of claim 36 wherein said branched alkyl group hasthe formula IV


38. A composition made by the process which comprises combining anedible solubilizing agent, an effective amount of a suitableantioxidant, an effective amount of a suitable dispersant and a compoundof the formula I

wherein R¹ is an aliphatic or aromatic moiety having from one to about36 carbon atoms and each of R² and R³ is independently hydrogen with theproviso that only one of R² or R³ is hydrogen, or a radical of theformula II or formula III

wherein R⁴ is an alkyl, substituted alkyl, alkenyl or substitutedalkenyl group having from one to about 10 carbon atoms.
 39. Thecomposition of claim 38 wherein R¹ is an alkylene radical having from 2to 18 carbon atoms; each of R² and R³ is a radical of the formula IIwherein R⁴ is an alkyl radical having from 2 to 10 carbon atoms.
 40. Thecomposition of claim 38 wherein R¹ is an alkylene radical having 7carbon atoms and wherein each of R² and R³ is a radical of the formulaII wherein R⁴is a branched alkyl group having 10 carbon atoms.
 41. Thecomposition of claim 40 wherein said branched alkyl group has theformula IV


42. The composition of claim 38 wherein R¹ is an alkylene radical having8 carbon atoms and wherein each of R² and R³ is a radical of the formulaII wherein R⁴ is a branched alkyl group having 10 carbon atoms.
 43. Thecomposition of claim 42 wherein said branched alkyl group has theformula IV


44. The composition of claim 38 wherein R¹ is an alkylene radical having10 carbon atoms and wherein each of R² and R³ is a radical of theformula II wherein R⁴ is a branched alkyl group having 10 carbon atoms.45. The composition of claim 44 wherein said branched alkyl group hasthe formula IV


46. The composition of claim 38 wherein R¹ is an alkylene radical having11 carbon atoms and wherein each of R² and R³ is a radical of theformula II wherein R⁴ is a branched alkyl group having 10 carbon atoms.47. The composition of claim 46 wherein said branched alkyl group hasthe formula IV


48. A method of reducing the absorption of cholesterol into thebloodstream comprising orally introducing into the body an effectiveamount of a substance containing a β-sitostanol ester wherein the esteris made by reacting β-sitostanol and a carboxylic acid in the presenceof an effective amount of a catalyst selected from the group consistingof calcium oxide, calcium hydroxide, a calcium salt of a carboxylicacid, magnesium hydroxide and combinations thereof.
 49. The method ofclaim 48 wherein the substance containing a β-sitostanol ester iscomprised of an additive comprised of from about 70% to about 80%sunflower oil, rape seed oil or a combination thereof; from about 1% toabout 2% vitamin E, an extract of the bark of the maritime pine, Pinusmaritima or a combination thereof; and from about 10% to about 25% of aβ-sitostanol fatty acid ester prepared by the method according to theinvention.
 50. The method of claim 48 wherein an effective amount of thesubstance is from about 0.2 to about 2.0 grams per day.
 51. The processof claim 48 wherein the catalyst is calcium hydroxide, calcium oxide ora calcium salt of a carboxylic acid.
 52. The process of claim 48 whereinthe carboxylic acid is a carboxylic acid having from about 2 to 22carbon atoms.
 53. A process which comprises reacting a sterol, a stanol,or a combination thereof with a carboxylic acid in the presence of aneffective amount of a catalyst selected from the group consisting ofcalcium oxide, calcium hydroxide, a calcium salt of a carboxylic acid,magnesium hydroxide and combinations thereof.
 54. The process of claim53 wherein said sterol is β-sitosterol.
 55. The process of claim 53wherein said stanol is β-sitostanol.
 56. The process of claim 53 whereinsaid catalyst is calcium hydroxide, calcium oxide or a calcium salt of acarboxylic acid.
 57. The process of claim 53 wherein said carboxylicacid is a carboxylic acid having from about 2 to 22 carbon atoms.
 58. Aprocess which comprises reacting β-sitostanol with a carboxylic acid inthe presence of an effective amount of calcium oxide.
 59. The process ofclaim 58 wherein said carboxylic acid is a carboxylic acid having fromabout 2 to 22 carbon atoms.
 60. The process of claim 59 wherein saidcarboxylic acid is a mixture of long chain carboxylic acids derived fromsunflower oil, palm kernel oil, coconut oil, rape seed oil, tallow, cornoil, canola oil, linseed oil, palm oil, olive oil, sesame oil, saffloweroil.
 61. A process which comprises the steps of: (1) forming a reactionmixture comprised of a sterol, a stanol, or a combination thereof with acarboxylic acid in the presence of an effective amount of a catalystselected from the group consisting of calcium hydroxide, magnesiumhydroxide and a combination in a reaction zone; (2) passing at least aportion of said reaction mixture through an evaporation zone to removethe water of reaction from said reaction mixture.
 62. The process ofclaim 61 further comprising the step of returning the mixture from step(2) to said reaction zone.
 63. The process of claim 61 wherein saidcatalyst is calcium oxide.
 64. A process which comprises reacting asterol, a stanol or a combination thereof with an carboxylic acid esterin the presence of an effective amount of a catalyst selected from thegroup consisting of calcium oxide, calcium hydroxide, a calcium salt ofa carboxylic acid, magnesium hydroxide and combinations thereof.
 65. Theprocess of claim 64 wherein said sterol is β-sitosterol.
 66. The processof claim 64 wherein said stanol is β-sitostanol.
 67. The process ofclaim 64 wherein said catalyst is calcium hydroxide, calcium oxide or acalcium salt of a carboxylic acid.
 68. The process of claim 64 whereinsaid carboxylic acid is a carboxylic acid having from about 2 to 22carbon atoms.
 69. The process of claim 64 wherein said ester is a methylester of a C₆₋₂₂ fatty acid or a triglyceride.
 70. A process whichcomprises reacting β-sitostanol with a carboxylic acid ester in thepresence of an effective amount of calcium oxide.
 71. A process whichcomprises the steps of: (1) forming a reaction mixture comprised of asterol, a stanol, or a combination thereof with a carboxylic acid esterin the presence of an effective amount of a catalyst selected from thegroup consisting of calcium hydroxide, magnesium hydroxide and acombination in a reaction zone; (2) passing at least a portion of saidreaction mixture through an evaporation zone to remove the water ofreaction from said reaction mixture.
 72. The process of claim 71 furthercomprising the step of returning the mixture from step (2) to saidreaction zone.
 73. A compound of the formula I

wherein R¹ is an aliphatic or aromatic moiety having from one to about36 carbon atoms and each of R² and R³ is independently hydrogen with theproviso that only one of R² or R³ is hydrogen, or a radical of theformula II or formula III

wherein R⁴ is an alkyl, substituted alkyl, alkenyl or substitutedalkenyl group having from one to about 10 carbon atoms.
 74. The compoundof claim 73 wherein R¹ is an alkylene radical having from 2 to 18 carbonatoms; each of R² and R³ is a radical of the formula II wherein R⁴ is analkyl radical having from 2 to 10 carbon atoms.
 75. The compound ofclaim 73 wherein R¹ is an alkylene radical having 7 carbon atoms andwherein each of R² and R³ is a radical of the formula II wherein R⁴ is abranched alkyl group having 10 carbon atoms.
 76. The compound of claim73 wherein said branched alkyl group has the formula IV


77. The compound of claim 73 wherein R¹ is an alkylene radical having 8carbon atoms and wherein each of R² and R³ is a radical of the formulaII wherein R⁴ is a branched alkyl group having 10 carbon atoms.
 78. Thecompound of claim 77 wherein said branched alkyl group has the formulaIV


79. The compound of claim 77 wherein R¹ is an alkylene radical having 10carbon atoms and wherein each of R² and R³ is a radical of the formulaII wherein R⁴ is a branched alkyl group having 10 carbon atoms.
 80. Thecompound of claim 77 wherein said branched alkyl group has the formulaIV


81. The compound of claim 73 wherein R¹ is an alkylene radical having 11carbon atoms and wherein each of R² and R³ is a radical of the formulaII wherein R⁴ is a branched alkyl group having 10 carbon atoms.
 82. Thecompound of claim 81 wherein said branched alkyl group has the formulaIV


83. A compound which is the product of the process which comprisesreacting a sterol, a stanol, or a combination thereof with adicarboxylic acid in the presence of an effective amount of a catalystselected from the group consisting of calcium oxide, calcium hydroxide,a calcium salt of a carboxylic acid, magnesium hydroxide andcombinations thereof.
 84. The compound of claim 83 wherein said stanolis a compound of the formula VI

wherein R⁴ is an alkyl, substituted alkyl, alkenyl or substitutedalkenyl group having from one to about 10 carbon atoms.
 85. The compoundof claim 84 wherein said dicarboxylic acid is azelaic acid and whereinsaid branched alkyl group of the formula IV


86. The compound of claim 84 wherein said dicarboxylic acid isdodecanedioc acid and wherein said branched alkyl group of the formulaIV


87. The compound of claim 84 wherein said dicarboxylic acid is brassylicacid and wherein said branched alkyl group of the formula IV


88. The compound of claim 83 wherein said sterol is a compound of theformula VII

wherein R⁴ is an alkyl, substituted alkyl, alkenyl or substitutedalkenyl group having from one to about 10 carbon atoms.
 89. The compoundof claim 88 wherein said dicarboxylic acid is azelaic acid and whereinsaid branched alkyl group of the formula IV


90. The compound of claim 88 wherein said dicarboxylic acid isdodecanedioc acid and wherein said branched alkyl group of the formulaIV


91. The compound of claim 88 wherein said dicarboxylic acid is brassylicacid and wherein said branched alkyl group of the formula IV


92. The compound of claim 83 wherein said catalyst is calcium oxide.